Control of underground mining machines



Oct. 15, 1968 R. TEALE CONTROL OF UNDERGROUND MINING MACHINES 5 Sheets-Sheet 1 Filed Jan. 23, 1967 Oct 15, 1968 R. TEALE CONTROL OF UNDERGROUND MINING MACHINES 5 Sheets-Sheet 2 Filed Jan. 23, 1967 Oct. E5, 1968 R. TEALE 3,405,608

CONTROL OF UNDERGROUND MINING MACHINES Filed Jan. 23, 1967 S-Sheets-Sheec 3 FIG. 3.

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ZOA 2 B ZOC ZOD United States Patent 3,405,608 CONTROL OF UNDERGROUND MINING MACHINES Ronald Teale, Sunbui'y-on-Thames, England, assignor to Coal Industry (Patents) Limited, London, England, a company of Great Britain FiledJan. 23, 19 67, Ser. No. 610,951 Claims priority, application,Great Britain, Jan. 28, 1966, 3,966/ 66 Claims. (Cl. 91-412) ABSTRACT THE DISCLOSURE This invention relates to the control of underground mineral mining machines, and more particularly to the control of the advance of an advanceable armoured face conveyor.

It is an object of the present invention to provide a control system which permits operation from a location close to the machine of the advance of the conveyor at a predetermined distance from the machine during its travel in either direction along the face.

A system allowing the conveyor to be advanced either by the coal winning machine operator or by the powered supports operator saves the cost of a third operator who would otherwise be requiredfor that purpose. If the system can. be energised by the machine operator as he passes along the face, it has the advantage that the conveyor can be advancing while other work is being performed, whereas if it has to be energised by the powered supports operator it has the disadvantage that he must wait until the conveyor has advanced over the section ahead of him before he can proceed to advance further supports. Systems for causing the conveyor to be advanced by the machine operator are known but require the use of a number of pilot-operated valves. The present invention has the merit of simplicity in that no pilotoperated valves are required and the costand complexity of the control gear and hoses is kept to a minimum.

The present invention has also particular application to power loading installations in which it is desirable to advance, i.e. snake, the conveyor as close as possible behind the machine in order to minimise the possibility of loose coal falling from the face into the area between the conveyor and the face and thereby rendering the advance of the conveyor more difiicult. With a view to overcoming this difiiculty scavenger ploughs have been trailed behind the machine at the throat of the snake i.e. the point at which the advancing conveyor nearly touches the mineral face. The scavenger plough effectively cleans up spillage coal left by the power loader itself and coal which may have fallen from the face.

According to the invention there is provided a control system for a snakable conveyor, comprising a plurality of hydraulic rams connected at spaced intervals along the conveyor and a plurality of control means each adapted to control the operation of an associated ram or group of rams, each said control means being interconnected with two of said control means in such manner that the operation of any control means simultaneously initiates operation of the ram or rams associated with one of the control means interconnected therewith, and conditions the ram or rams associated with itself for initiation by subsequent operation of the remaining control means interconnected therewith.

Preferably the system includes a first control valve for each ram for controlling the feed and discharge of operating fluid to and from the ram, and wherein each control means includes a second control valve each second control valve being adapted to over-ride the operation of the first control valves of the rams controlled by the two control means interconnected therewith.

The second valves are preferably three position valves, having an OFF position and two alternative ON positions in which they over-ride a first control valve.

The second valves may be manually, mechanically or remotely operated.

Furthermore, the first valves are preferably three position valves having an OFF position and two alternative ON positions in which they cause the rams to change their condition. The first valves may be locally or remotely operated.

Reference will now be made to the accompanying drawings in which FIGURE 1 is a schematic diagram illustrating a first embodiment of a hydraulic control circuit for the advancing rams of a mine face conveyor.

FIGURE 2 is a schematic diagram illustrating a modification of the embodiment of FIGURE 1 and FIGURE 3 is a schematic diagram illustrating a further embodiment of a hydraulic control circuit for the advancing rams of a mine face conveyor.

Referring to FIGURE 1, double acting rams 1 used for pushing over a snakable armoured face conveyor 2 are arranged at intervals along a longwall face 2A, and are connected to the conveyor by suitable coupling means 2B. A machine 2D is movable along the face. Each ram 1 is controlled by a valve 3 which is fed from a main pressure line 4 through a conduit orduct 5. Exhaust fluid from each ram is carried away by a main return line 6 which is connected to the valve 3 by a conduit or duct 7. Each valve is connected to the pushing side of the ram 1 by a conduit or duct 8 and to the ram pulling side by a conduit or duct 9. For convenience, the individual rams are uniquely identified as 1A, 1B, 1C and 1D. The valves 3 and ducts 5, 7, 8 and 9 associated with the rams 1A, 1B, 1C and 1D, are uniquely identified as shown in the figure, by means of the appropriate suflix A, B, C or D.

The ram control valve 3A is a three position valve capable of manual and/or pilot operation. In its normal central position the ducts 5A and 8A are closed and the duct 9A is connected to the duct 7A. Thus, the pushing side of the ram 1A is closed and the pulling side is vented to the return line 6. In one operated position, the valve 3A connects the duct 5A to the duct 8A, duct 7A being left connected to duct 9A. In this position of the valve 3A the ram 1 is set to the conveyor pushing condition, i.e. the conveyor section to which the ram is coupled is advanced. In its other operated position, the valve 3A connects the duct 5A to the duct 9A and the duct 8A to the duct 7A. In this valve position the ram. is set to the pull condition i.e. the body of the ram 1A is advanced together with any equipment, such as a mine roof support attached thereto. A similar set of operational connections and conditions pertains to the other valves 3B, 3C and 3D and their associated rams and ducts. This manner of operating the rams is known and may be effected such that the rams 1 may each be operated individually, either to pull or to push.

According to the invention, an additional control means 3 is provided for each ram 1A, 1B, 1C or 1D. For the ram 1A, this additional control means includes a valve 10A- fed from the main pressure line 4 by means of the conduits or ducts 5 and 11. The valve A is connected to the pushing side of the ram 1 by means of ducts 12A and 8A. The rams 1B, 1C and ID are similarly associated with valves 10B, 10C and 10D, the latter being connected into circuit by ducts 11B, 11C, 11D and 12B, 12C and 12D in the manner described in relation'to the valve 10A. Each valve 10 is connected to the valves 10 of adjacent rams 1 on either side by ducts 13.

Thus the valve 10A is connected by a duct 13A to the valve of the adjacent ram (not shown) located to the left hand side of the ram 1A, and by a duct 13B to the valve 10B. The valve 10B is connected by a duct 13C to the valve 10C. The valve 10C is connected by a duct 13D to the valve 10D. The valve 10D is connected by a duct 13E to the valve 10 (not shown) associated with the adjacent ram (not shown) located to the right hand side of the ram 1D.

Each valve 10 is a three position valve capable of manual or mechanical operation. It is intended that it should be operated, either manually by the machine operator or mechanically by the machine itself, whenever the machine passes it. Once operated it maintains the position until restored by a means to be described later.

If the machine 2D is advancing in a direction from left to right of the drawing, it is intended that each valve 10 should be operated in such a manner that a duct 11 is connected to the duct 13 leading to the left and the duct 12 is connected to the duct 13 leading to the right. Thus, fluid pressure will be supplied from the duct 11 through the duct 13 leading to the left to the preceding valve 10, which, having already been operated in like manner, will pass the fluid through its own duct 12 into the pushing side of its own ram 1. Thus, as each valve 10 is operated the preceding ram 1 will be caused to push.

If the machine is advancing in a direction from right to left of the diagram, each valve 10 is operated in such a manner that the duct 11 is connected to the duct 13 leading to the right and the duct 12 to the duct 13 leading to the left. Again, the effect of operating the valve 10 is to cause the preceding ram 1 to push.

Since the stroke of each ram 1 is arranged to be equal to the width of the web of coal taken off by the machine the rams can be allowed to push indefinitely. In practice it is necessary to follow up the advance of the conveyor by advancing the means (powered support or stells) used as abutments or anchorages for the rams 1. This is effected by putting the rams 1 onto pull by means of the valve 3 as previously described. Before this can be done, however, it will be necessary to restore each valve 10 to its normal central position. This may be done either manually or by pilot operation, eg by a tapping from the duct 9 which applies pressure (by means not shown in the drawing) to restore valve 10 to its central position whenever pressure is applied to the pulling side of ram 1. Thus, the valves 10 may be re-set before the next passage of the machine through the face.

In the event that the control system of FIGURE 1 causes the conveyor 2 to be advanced too close to the machine each valve 10 may be connected not to the valves 10 of the adjacent rams but to the valves 10 of the nextbut-one rams. FIGURE 2 illustrates such an arrangement.

In FIGURE 2 the same reference numerals have been used to identify valves and ducts already shown in FIG- URE 1. In FIGURE 2 the arrangement of the ducts interconnecting the valves 10, is such as to replace the ducts 13 of FIGURE 1 by two overlapping but separate systems of ducts 14 and 15. The valve 10A is connected to the valve 10C by a duct 15C, and to the valve 10 associated with a ram located next but one to the ram 1A by a duct-15A. The valve 10B is connected by a duct 14B to the valve 10 of the ram immediately adjacent to the ram 1A, and by a duct 14D to the valve 10D. The valve 10C is connected by the duct 15C to the valve 10A and by the duct 15E to the valve 10 of the ram immediately adjacent to the ram 1D. The valve 10D is, as previously mentioned, connected by the duct 14D to the valve 10B and by the duct 14F to.th e valve 10 of the ram located next but one to theram 1D. i I ,3

The mode of operation of the control system shown in FIGUREZ is similar to that of FlGURE 1, except that the operation of any valve 10 causes the next but one, ram 1 in the control sequence to advance.

By varying the spacings of the rams 1' and the number of overlapping sets of ducts interconnecting the valves 10 various control requirements can be attained.

It is to be understood also that the valves 10 may not only directly feed the push rams 1 but may feed auxiliary cylinders, the purpose of which is to obtain conveyor advance in fixed increments of less than the total ram stroke.

FIGURE 3 illustrates an embodiment of the conveyor control system in which groups or-sets of rams l are operated inan overlapping sequence. In the schematic hydraulic circuit of FIGURE 3 those valves and ducts which fulfill functions similar to corresponding valves and ducts of the control system of FIGURE 2 have been identified by the same references. In FIGURE 3 a plurality of hydraulic rams 1A to 15 are connected at spaced intervals to the face conveyor 2. Each ram is controlled by a control valve 3. Each control valve 3 is connected to a main pressure line 4 by a duct 5; to a return line 6 by a duct 7; to the pushing side of the ram by a duct 8 and to the pulling side of the ram by a duct 9. In the drawing'the control valves 3 and the ducts 5, 7, 8 and 9 associated with the various rams 1A to 18 are uniquely identified by corresponding suffixes. Only a few of the ducts 7, 8, 9 have been shown in FIGURE 3 for the sake of clarity.

The control circuit includes second control-valves 16 which perform the functions of the control valves 10 of the control systems of FIGURES 1 and 2. FIGURE 3 illustrates five such valves 16 which are uniquely identified as 16A, 16B, 16C, 16D and 16B, these valves being respectively fed from the main pressure line 4 by means of ducts 17A, 17B, 17C, 17D and 17B. The ducts 17A, 17B, 17C, 17D and 17E respectively connect with further ducts 18A, 18B, 18C, 18D and 18E. Each of these latter mentioned ducts connects with a group of the ducts 5. Thus as will be seen in the figure the duct 18A connects with the ducts 5C, SD, SE and SF, the duct 18B connects with ducts 56, 5H, 51 and 5]. By means of the above described connections each one of the rams 1 may be operated individually either to push the conveyor forward or to pull up the body of the ram in the manner described in relation to FIGURE 1.

Each of the valves 16 is connected to each of the immediately adjacent valves 16 by ducts 19. The valve 16A is connected by a duct 19A to the adjacent valve 16 (not shown) located to the left hand side thereof and by a duct 198 to the valve 16B. The valve 16C is connected to the valve 16B by a duct 19C and by a duct 19D to the valve 16D. The valve 16E is connected by a duct 19E to the valve 16D and by a duct 19F to the immediately adjacent valve 16 to the right of valve 16E.

Any selected number of the rams 1 may be designated to be used together for advancing a section of the conveyor 2. In FIGURE 3 it is intended that four side-by-side rams should be operated at the same time, and for this purpose each duct 19 is connected through non-return valves 20 to the ducts 12 associated with four of the control valves. Thus for example, the duct 19B is connected to the ducts 12C, 12D, 12B and 12F associated with the valves 3C, 3D, 3E and SF through non-return valves 20C, 20D, 20E and 20F. Similar connections, not shown are made between the other valves 3 and the other ducts 19.

The valves 16 are spaced along the length of the face 2A and are interconnected with each other by ducts 14 5 and 15. The ducts 14, 15 interconnect the valves 16 in the manner described in relation to FIGURE 2.

If the coal winning machine 2D is advancing in a direction from left to right of the FIGURE 3, it is intended that each valve 16 should be operated in such manner that the duct 17 is connected to the duct 14 or 15 leading to the left. The duct 19 leading to the right is connected to the duct 14 or 15 leading to the right and the duct 19 leading to the left remains closed. Thus, fluid pressure, will be supplied from the duct 17 through the duct 14 or 15 leading to the neXt-but-one preceding valve 16 which having already been operated in like manner, will pass the fluid through its own duct 19 leading to the right and cause the group of four rams 1 immediately to the right to push. Thus, as each valve 10 is operated the neXt-but-one preceding group of four rams will be caused to push.

If the machine is advancing in a direction from right to left of the drawing, each valve 16 is operated in the opposite sense with the result that the neXt-but-one preceding group of four rams 1 will be caused to push.

It will be seen that if the machine is advancing from left to right, the fluid causing each group of rams to push passes through the valve 16 at its left-hand end so that an operator following the machine 2D may cancel the pushing of each group of rams in front of him by restoring the appropriate valve 16 at the start of the group to the neutral position.

Similarly, when the machine is travelling from right to left the fluid causing each group of rams to push passes through the valve to the right hand end of the bank so that the operator may again cancel the pushing operation of each group as he reaches it.

I claim:

.1. A control system for a snakable conveyor comprising a plurality of hydraulic rams connected at spaced intervals along the conveyor and a plurality of control means each associated with at least one of said rams in such manner as to control the operation of each associated ram, each said control means being interconnected with two of said control means in such manner that the operation of any control means simultaneously initiates operation of each ram associated With one of the control means interconnected therewith, and conditions each ram associated with itself for initiation by subsequent operation of the remaining control means interconnected therewith.

2. A control system as claimed in claim 1, wherein each control means is interconnected with the two control means associated with the immediately adjacent rams.

3. A control system as claimed in claim 1, wherein each control means is interconnected with two control means associated with rams other than those associated with the immediately adjacent rams.

4. A control system as claimed in claim 1 and comprising a first control valve for each ram for controlling the feed and discharge of operating fluid to and from the ram, and in which each said control means includes a second control valve each second control valve overriding the operation of the first control valves of the rams controlled by the two control means interconnected therewith.

5. A control system as claimed in claim 4, when a control means is associated with more than one ram the rams are connected in parallel with a control output from the associated control means, and wherein each such ram is connected to the control output through a non-return valve.

No references cited.

EDGAR W. GEOGHEGAN, Primary Examiner. 

